Abstract patterns by Mexican artist David Alfaro Siqueiros are the result of a well-studied problem in fluid dynamics.

Roberto Zenit at the National Autonomous University of Mexico in Mexico City and his team replicated the artist's 'accidental painting' technique, in which layers of paint are poured on a horizontal surface, over time creating whorls, blobs and other shapes. The authors successfully produced patterns similar to those in Siqueiros's work using a dense fluid on top of a light one — an unstable arrangement because the heavier liquid pushes through the light one, forming characteristic shapes.

This 'Rayleigh–Taylor instability' between two fluids has already been widely studied because it is important in many natural and engineering systems. An experimental arrangement similar to that used by Siqueiros could help physicists to advance such studies, the authors say.

PLoS ONE http://doi.org/10.1371/journal.pone.0126135 (2015)